A flood-related outbreak of carbon monoxide poisoning—Grand Forks, North Dakota

Post-disaster carbon monoxide (CO) poisoning is a growing problem in the United States. This study describes a documented outbreak of CO poisoning associated with flooding. Health department staff investigated cases of CO poisoning following the severe flood of 1997 in Grand Forks, North Dakota. Thirty-three laboratory-confirmed cases were identified, involving 18 separate incidents. Patients ranged in age from 7 to 67 years, and most were men. One patient lost consciousness and was admitted to the hospital; all others were released after receiving supplemental oxygen. Every incident involved gasoline-powered pressure washers being used in basements. Five incidents among professional cleaners accounted for 16 cases; the remaining incidents involved noncommercial use. Thirty patients, from 15 incidents, reported the basement was ventilated while the pressure washer was in use. CO poisoning must be considered a potential hazard after major floods.